The invention is directed to the coupling of a sewer treatment station-STS—to a treatment plant for the flocculation and flotation of water streams and, more specifically, to the insertion of a sewer treatment station—STS—as a dynamic primary treatment stage in the optimization of the treatment process for the flocculation and flotation of water streams in urban regions and/or regions nearby.
Further, it is related to the insertion of a treatment plant for the flocculation and flotation of water streams into a water treatment station—WTS—and, more specifically, to an adaptation in the Water Treatment Station—WTS—inserted for the optimization of the treatment process in preexisting conventional installations and/or design of new installations.
In general lines, urbanization is based on the water availability for impounding drinking water to supply the public. Notably, except for a few cases, cities are created and developed next to water bodies, from which the water is impounded that will ultimately generate several urban uses.
Generally, urban growth takes place towards the main sources of water resources. Usually, springs and dams are physically involved in the urban border of large cities.
Besides this physical expansion and the demographic growth, the production of domestic and industrial waste, solid and semi-solid debris and liquid effluents also constitutes a phenomenon of urbanization, more intensively in large cities.
The implementation of exhaustion systems with the collection, removal and treatment of effluents and sewer constitutes another necessity and essential condition for the urban development.
Briefly, the urban break-even point is attained through the cycle whose steps are: (a) water impound for supplying; (b) generation of debris and effluents (sewer); (c) impound and removal of effluents; (d) treatment of effluents; (e) post-treatment launching of effluent into water bodies; and (f) self-purification in water bodies.
Usually, the intense urbanization of the hydrographic basins causes a break in the established balance that is evidenced through the higher production of debris and effluents than the capacity of self-purifying water bodies. Therefore, the environmental deterioration of the water impounds and the gradual loss of the water quality appear as a common denominator in densely urbanized areas.
Thus this deterioration and pollution of water streams is aggravated with the demographic growth, thus consequently increasing the pollution that is continuously launched into watercourses.
More specifically, with regard to the sewer treatment systems object of the present invention in regions showing an organized urban concentration, the latter can be classified in four categories, viz: a) the cities that do not have any type of impound, removal and sewer treatment station, wherein all sewer and served water generated by the urban concentration is launched into the pluvial water network, that in turn heads for the bed of streams or secondary rivers that flow to water bodies, the main ones for the region, that in turn can cross several cities until the flow to the sea or a dam; b) there are cities that are provided with single sewer treatment systems that collect of individually or collectively (sectors) the sewer generated by the urban concentration and then launches same into the pluvial water network being treated in STS's except in the rain, and from this point onwards the treated sewer is conveyed in the same way previously described until it reaches the course of main or huge water bodies; c) there are cities, however, that are provided with a whole separating system for the load of sewer generated, and in this in case all the sewer generated by the urban concentration is collected and conveyed to a treatment station, wherein the debris are removed and purified and the residual water, after being treated, is launched into the water streams and/or dams; and d) there are cities, irrespective of their size, whose sewer treatment system is a combination wherein part of the population uses a single sewer collection system, others use a whole separating system and there also is a part of the population that does not use any sewer collection or treatment system, launching the latter into water bodies, either directly or through the existing pluvial water network.
Also considering that a water body crosses throughout its whole course innumerable poles of urban concentration that are embodied in the above-mentioned different standards, it is evident that the contamination and pollution level downstream a water body is significantly larger, thus inevitably impairing the urban concentration geographically situated in this portion of the water body, or in the event it is not nearby, it is supplied with the waters from said water body.
For the treatment of water bodies, the process for removing pollutant materials and/or substances contained in water streams, which is an object of patent document U.S. patent application Ser. No. 10/167,089, of Jun. 10, 2002 and Brazilian patent document No. PI0105462-7, of Jun. 11, 2001, which process guarantees the elimination of the aspects that offend the aesthetic sense, as well as the conservation of the natural water resources against severe pollution and its maintenance under full use conditions, either in the containment of water resources for future reutilization; either in the implementation and development of industries, or in the use of urban water streams as recreational and sports elements.
However, the process defined in patent document U.S. patent application Ser. No. 10/167,089, of Jun. 10, 2002 and Brazilian patent document No. PI0105462-7, of Jun. 11, 2001, whose steps are carried out along the water stream itself, provides a continuous dynamic flotation treatment of the whole volume of water that crosses same, so that the already treated water flowing downstream this process area is still vulnerable to new foci of pollution if any type of additional procedure for containing the spill of sewer discharges in this water body is not adopted.
Ideally, all the urban concentrations should in effect have at least one a sewer treatment station—STS—which can carry out at least a primary treatment of the sewer collected in order to reduce the contamination level of the water bodies that serve these urban concentrations.
Another ideal condition for any standard of urban concentration is that all the load of sewer generated for the community is collected and sent to a treatment station—STS—reducing the levels of sewer launched into water bodies to almost zero. Sometimes said level does not reach 100% because there always will be clandestine launching of sewer water bodies, either directly or indirectly, through the pluvial water networks, either through main streams or secondary streams.
Another ideal condition, mainly for expanding cities, is the provision of a sewer treatment station—STS—that is dynamic, that is, that can be expanded as the urban concentration increases, thus preventing the possibility of collapse of an existing station and not requiring, to prevent a possible collapse of the treatment facility, a large initial investment in the construction of a huge station that will remain idle in the beginning, while a predicted demographic expansion does not occur.
Therefore one of the objects of the present invention is to provide the coupling of a sewer treatment station—STS—to a treatment plant for the flocculation and flotation of water streams that makes it possible to direct all the sewer generated in the urban concentration thus thoroughly saving the stream bed of the main water stream, that in turn is already provided with the dynamic flotation treatment process, that will be a secondary or even tertiary sewer treatment step in said coupling.
Another object of the present invention is to provide a coupling of a sewer treatment station—STS—to a treatment plant for the flocculation and flotation of water streams that guarantees an anticipated definition of the quality of treated water without generating any loss in terms of investments in sewer networks, removals and STS's of any urban concentration.
Still another object of the present invention is to provide a coupling of a sewer treatment station—STS—to a treatment plant for the flocculation and flotation of water streams that can be dynamically installed, that is, the expansion of which is determined according to the expansion of the urban concentration that generates the sewer collected, thus preventing the huge size of the installations generally carried through in order to prevent a collapse of the system.
Another object of the present invention is to provide a coupling of a sewer treatment station—STS—to a treatment plant for the flocculation and flotation of water streams that can be installed both next to the stream bed of the water body that already is under the treatment process for the flocculation and flotation and far from said water body, provided that the outlet drain of said sewer treatment station—STS—is directly connected to the inlet of the station that promotes the treatment for the flocculation and flotation of the water body.
Considering that in an urban system besides the sewer treatment stations—STS's—the existence of water treatment stations—WTS's—is essential; and considering that the conventional or classical water treatment stations—WTS's—carry out the treatment in separate compartments usually comprised of: fast mixers, flocculators, decanters, filters and contact tank, wherein the suitable sanitation of the water is assured; it should be emphasized in general terms that said conventional or classic treatment stations that treat the water through flocculation, decantation and filtration can eliminate only the colloids and suspended material present therein, that drag the pathogenic organisms associated thereto. Other remaining organisms not provided with possible protective barriers, are submitted sequentially to a sanitation process, usually through chlorination, and are then eliminated.
Thus, not only the sewer to be launched into fluid beds presents risk to the population but also in view of the sanitation issue, the way the supplying water is treated is worrisome, considering that the water-borne illnesses still constitute the cause of a significant percentage of deaths. With the exception of the poisonings produced by waste substances generated by industrial activities, the water-borne illnesses are caused by such microorganisms as viruses, bacteria, protozoa and worms. Considering that the waters launched into the riverbeds will be impound and contained later on to serve as supply water to another urban center, it is also important that the, besides STS's, WTS's are also submitted to an effective sanitation treatment.
Thus, another object of the present invention is to provide the insertion of a treatment plant for the flocculation and flotation of water streams into a preexisting conventional type water treatment station—WTS—and/or that said insertion is implemented in a new unit designed according to the treatment plant described herein-above, thus allowing among others the optimization of the process for removing protozoa such as “Cryptosporidium sp”; “Cyclospora”; “Isospora belli”; and “Microsporiodeo sp”, and the removal of practically all the seaweed that can hardly be removed by the conventional treatment processes.
Still another object of the present invention is to provide an insertion of a treatment plant for the flocculation and flotation of water streams into a water treatment station—WTS—having a longer useful life, thus reducing the maintenance costs in relation to the conventional Water Treatment Stations.
Another object of the present invention is to promote the insertion of a treatment plant for the flocculation and flotation of water streams into a water treatment station—WTS—that promotes the treatment through flocculation, decantation and filtration, replacing the flocculation and decantation phases, by the treatment process for the flocculation and flotation of fluid beds, used in patent document U.S. Ser. No. 10/167,089, of Jun. 10, 2002 and relevant Brazilian patent document No. PI0105462-7, of Jun. 11, 2001, through the use of the preexisting WTS tanks without the need to include a new constructive device.
Another object of the present invention is to provide the insertion of a treatment plant for the flocculation and flotation of water streams into a water treatment station—WTS—with a larger capacity for producing water for the consumption that can operate with varying flow rates.